File Size Converter
Convert bytes, KB, MB, GB, and TB.
The File Size Converter lets you convert between all common digital storage units: bytes, kilobytes (KB), megabytes (MB), gigabytes (GB), and terabytes (TB). Choose between binary (base-2: 1 KB = 1,024 bytes) and decimal (base-10 SI: 1 KB = 1,000 bytes) calculation modes, since storage manufacturers use decimal while operating systems use binary — which is why a "1 TB" hard drive shows up as about 931 GB in Windows or macOS. Useful for understanding storage requirements, comparing device capacities, estimating upload/download times, and database storage planning.
File Size Converter
Formula
Examples
1.5 GB to MB
Convert 1.5 gigabytes to megabytes.
→ 1,536 MB (binary) or 1,500 MB (decimal)
500 GB Hard Drive — Actual Usable Space
A 500 GB (decimal) hard drive shows how many GB in Windows?
→ 500 GB (decimal) = ~465.7 GiB (what Windows/macOS shows as "GB")
4K Video File: 40 GB to TB
A 40 GB 4K movie file in terabytes.
→ 0.039 TB (decimal) / 0.0391 TiB (binary)
Tips
- ✓1 photo ≈ 3–5 MB | 1 song ≈ 4–7 MB | 1 HD movie ≈ 4–8 GB | 1 4K movie ≈ 20–80 GB.
- ✓Use binary (1024) when checking RAM and OS reported file sizes; use decimal (1000) for hard drive specs.
- ✓Data transfer speeds (internet, USB) are measured in bits (lowercase b), not bytes: 1 Mbps = 0.125 MB/s.
- ✓Email attachment limits: Gmail/Outlook typically 25 MB. For larger files, use cloud storage links.
Frequently Asked Questions
What is the difference between KB and KiB?
1 KB (kilobyte, SI standard) = 1,000 bytes. 1 KiB (kibibyte, IEC standard) = 1,024 bytes. Hard drives and SSDs are marketed using decimal (KB=1,000), but operating systems measure using binary (KiB=1,024). This is why a "500 GB" drive shows ~465 GB in Windows.
Why does my "1 TB" drive show less than 1 TB in Windows/macOS?
Storage manufacturers use decimal: 1 TB = 1,000,000,000,000 bytes. Operating systems use binary: 1 TB (OS) = 1,099,511,627,776 bytes. So 1 TB (decimal) = 1,000,000,000,000 ÷ 1,099,511,627,776 ≈ 0.909 TB in OS notation, which displays as approximately 931 GB.
How many MB are in a GB?
Binary: 1 GB = 1,024 MB. Decimal (SI): 1 GB = 1,000 MB. Most storage device specs use decimal; RAM, OS file sizes, and RAM use binary.
How do I calculate file transfer time?
Time (seconds) = File size (in bits) / Transfer speed (in bits per second). Note: 1 MB = 8 Mb (megabits). A 100 MB file over a 100 Mbps connection takes 100 MB × 8 / 100 Mbps = 8 seconds (ignoring overhead).
What are typical file sizes for common content?
Photo (JPEG): 2–5 MB. RAW photo: 20–40 MB. Song (MP3): 3–7 MB. HD movie (1080p): 4–8 GB. 4K movie: 20–80 GB. 1-hour Zoom recording: 500 MB–1 GB. Email attachment limit: typically 25 MB (Gmail/Outlook).
What is a terabyte in context?
1 TB can store approximately: 250,000 photos (at 4 MB each), 200,000 songs (at 5 MB each), 125 HD movies (at 8 GB each), or about 6.5 million documents (at 150 KB each). A standard Netflix 4K stream uses about 7 GB per hour.